The entire UI for orbiter can be changed beyond anything that XBMC can concieve.. but it does take a considerable amount of time investment, because you are essentially developing user interfaces not only for on-screen displays, but also for PDAs, tablets, cell phones, and other portable devices that can control a LinuxMCE system as well.

I will be posting a series of screencasts on using HA Designer, and hopefully this will encourage people to step forward and help us work on more UI possibilities.

I think they are referring to the usability and simplicity of the skinning engine of XBMC. To be fair, LinuxMCE is capable of much more than XBMC, but as a user of the XBMC skinning engine (I wrote 90% of the original MC360 xml's if anyone follows the project), I can tell you it is much easier to work with XBMC's engine. I'd love to see progress made on the skinnability of LinuxMCE as I personally don't much care for the current LinuxMCE UI and would love to participate in projects towards alternatives, but the learning curve is quite steep currently.